KR19980019215A - Microcomputer with self-diagnostic unit - Google Patents

Abstract

In order to perform self-diagnosis of the CPU, the CPU monitor macro service is started in response to an interrupt signal from the outside. In the CPU monitor macro service, in accordance with the CPU monitor macro service code in the instruction code storage area, the CPU diagnostic initial value α, which has been recorded in RAM before the CPU monitor macro service is excited, is stored in the TA register. In addition, the address β indicating the output destination of the result of diagnosing the CPU using the initial value α is stored in the TC register. The initial value α is used for checking the address and path related to Lm and for checking the registers storing data in interrupt processing. The arithmetic operation unit ALU then performs an operation on the execution result value and sends the operation result value to the ALU register. Then, the execution result is transferred to the TA register, and is then output through the input / output port to the output destination of the external memory indicated by the address (β) stored in the TC register, whereby the state of the microcomputer can be checked externally. have.

Description

Microcomputer with Self Diagnosis Unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcomputer having a self-diagnostic unit, and more particularly to a CPU monitor macro service, which is a program for performing a series of instructions required for CPU diagnosis by an external interrupt signal. The present invention relates to a microcomputer having a self-diagnosis function for diagnosing a CPU in a microcomputer.

Recently, in order to improve the performance of a vehicle and to improve the safety thereof, an electronic controller having a microcomputer is generally used in a main controller of a vehicle such as an engine controller or a brake controller. If a user set or a microcomputer related to the engine controller and the brake controller fails, this may endanger human life. Therefore, microcomputers for use in this technical field require high reliability. To check whether a microcomputer has failed before using it for a user set, technicians in automotive controllers install the microcomputer on a user board and apply self-diagnostic software from the outside to the microcomputer. As a result, the self-diagnosis software diagnoses the CPU in the microcomputer and checks whether a failure occurs in accordance with the diagnosis result.

As described above, in the conventional microcomputer used in automobiles, the CPU diagnostic self-diagnosis software is applied to the microcomputer to check the state of the microcomputer after installing the microcomputer on the user board and before shipping the user set. In this case, CPU self-diagnosis is implemented in accordance with instructions from the CPU self-diagnosis software from the outside.

On the other hand, Japanese Laid-Open Patent Publication No. 60-183639 describes a macro service that executes a series of instructions by interruption. In the conventional macro service, the central processing unit includes data processing control means, which performs an arithmetic operation and changes the overall state immediately when the first process related to the program execution in the program memory is held. It provides the data stored in the memory without making it work. In response to a processing request from a counter, the data processing means performs the arithmetic operation and data provision. Thus, the conventional data processing apparatus reduces the time consumed by the interrupt and quickly returns to the first process.

However, the purpose of the conventional macro service is only to reduce the time required to execute an external program as interrupt processing, and not to reduce the time required for CPU diagnosis. With regard to CPU diagnostics, the publication of the above patent does not disclose or suggest a function or structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a microcomputer having a self-diagnosis unit capable of diagnosing a CPU in a short time by reducing the time spent reading instructions of the software as compared to a conventional microcomputer diagnosing the CPU by external software. will be.

According to the present invention, a microcomputer having a self-diagnosis unit employs a CPU monitor macro service that executes a series of instructions by interrupt, and then performs self-diagnosis of the CPU in the microcomputer after installing the microcomputer on the user board. .

According to a feature of the present invention, a microcomputer having a self-diagnostic unit, a randomly read and write RAM interrupt processing unit, a data bus, an input / output port, and an external interrupt signal execute a series of instructions to execute the microcomputer. A CPU monitor macro service which is a program for diagnosing a CPU; a CPU diagnostic unit for diagnosing a CPU of the microcomputer according to the CPU monitor macro service with reference to data supplied from the outside in advance; And an output unit for outputting the results diagnosed by the CPU diagnostic unit to the outside of the microcomputer.

According to another aspect of the present invention, a microcomputer having a self-diagnosis unit executes a series of instructions by a CPU, a randomly readable RAM, an interrupt processing unit, a data bus, an input / output port, and an external interrupt signal to execute the microcomputer. CPU monitor macro service, which is a program for diagnosing a CPU of a computer, a startup unit for starting the CPU monitor macro service, a micro ROM that is an instruction code storage space for storing instruction codes of the CPU monitor macro service, and a CPU of the micro ROM. A first register for storing and storing an initial value for performing the CPU diagnosis in RAM using a user program of an external memory before initiating the CPU monitor macro service according to the instruction code of the monitor macro service; Using a user program in external memory A second register for storing an address indicating an output destination for the result value of the execution after executing the CPU diagnostics according to the initial value recorded in the RAM, and checking the address and the path of the RAM using the initial value Storing a result of an arithmetic operation by a third register for storing data in interrupt processing, a destination unit instructing the third register, and an arithmetic unit for implementing an arithmetic operation on an execution result value of the check. Storing the result from the fourth register to the first register after the fourth register and the test, and outputting the execution result stored in the first register to the outside of the microcomputer through a port indicated by the second register; An output unit for performing the operation with reference to the execution result value outside of the microcomputer. The state of the CPLT group microcomputer is diagnosed.

1 shows the structure of an embodiment of a microcomputer with a self-diagnostic unit according to the invention;

FIG. 2 shows in detail the structure of an embodiment of a microcomputer with a self-diagnostic unit according to the invention; FIG.

Explanation of symbols for the main parts of the drawings

3: interrupt processing unit 4: data bus

5: input / output port 6: CPU monitor macro service

7: CPU diagnostic module 8: Output module

11: external memory

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a microcomputer having a self-diagnosis unit according to the present invention will be described with reference to the accompanying drawings.

1 is a diagram showing the structure of an embodiment of a microcomputer with a self-diagnostic unit according to the present invention, and FIG. 2 is a diagram showing the structure of the embodiment in detail.

First, the structure of an embodiment is described with reference to FIG.

As shown in Fig. 1, the microcomputer 10 according to the present invention includes a CPU 1, a RAM 2 capable of reading and writing arbitrarily, an interrupt processing unit 3, a data bus 4, an input / output port ( 5). And a self-diagnostic unit 9. The self-diagnosis unit 9 includes a CPU monitor macro service 6, a CPU diagnostic module 7, and an output module 8. The CPU monitor macro service 6 is a program that executes a series of instructions in response to an external interrupt signal. The CPU diagnostic module 7 diagnoses the CPU 1 by referring to the data in the external memory 11 in accordance with the CPU monitor macro service 6. The output module 8 outputs the diagnosis result of the CPU 1 to the outside using reference data.

Next, an embodiment of a microcomputer equipped with a self-diagnosis unit according to the present invention will be described in detail with reference to FIG.

In response to the interrupt signal 100 requesting CPU diagnostics, the micro ROM control circuit 101 starts a CPU monitor macro service that executes a series of instructions necessary for CPU diagnostics. Then, the micro ROM control circuit 101 which generates the address of the instruction code storage area corresponding to the instruction and interrupt signal designates the CPU monitor macro service code 102 to the micro ROM 115 which is the instruction code storage area. According to the CPU monitor macro service code 102, an initial value α and an address used for CPU diagnosis are stored in the TA register 114 and the TC register 112, respectively. The initial value α is written to the RAM 110 by the user program of the external memory 11 via the external signal line 127 before the CPU monitor macro service is started. The address indicates an output destination for the result value of executing the CPU diagnosis using the initial value α. The initial value α of the TA register 114 is used to sequentially check the function of the TB register 113 to save data in the address and interrupt processing of the RAM 110. After the checking, the arithmetic operation unit ALU 111 performs an operation on the execution result value and transfers the execution result operation value to the ALU register 126, whereby the result value is stored in the TA register 114. . Then, the execution result stored in the TA register 114 is output as the internal signal 120 of the microcomputer 125 through the port 118 designated by the address of the TC register 112, thereby allowing the user to execute the execution result. The value can be used to determine whether a fault has occurred.

The micro instruction 116 represents a block in which data should be output to the data bus 103. PSWL 119 is the lower 8 bits of the program status word. The special instruction 117 sets and resets the flag of the PSWL 119. SPH 108 is the upper 8 bits of the stack pointer consisting of the upper 4 bits of the register for storage. The SP 109 is the lower l6 bits of the stack pointer, which is the stack pointer including the lower 16 bits of the register that stores data during interrupt processing.

Next, the operation of the above embodiment is described.

The interrupt signal 100 activates a CPU monitor macro service for executing a series of instructions in response to the interrupt signal. The CPU monitor macro service uses the TA register 114 and the TC register 112 to output an initial address α for use in CPU diagnosis and an output destination address β of a CPU diagnostic execution result (hereinafter referred to as SFR output number). Each address is written to RAM 110 via an external signal line 127 using a user program of external memory 11 prior to initializing the CPU monitor macro service.

First, the address indicated by RAMAD (RAM address buffer 105) for preparing an address in RAM 110 is checked. Before starting the CPU monitor macro service, the value Va of the register stored in the RAM 110 is stored in the TB register 113. The initial value α is transferred from the TA register 114 to the register of the RAM 110 indicated by the RAMAD 105. Then, the RAMAD 105 instructs the register of the RAM 110 to store the initial value α. The register of the RAM l10 transfers the initial value α to the ALU 111, and at the same time the CPU monitor macro service code 102 starts the ALU 111 via the ALUDEC 107 specifying its operation. do. The ALU 111 executes the decrement operation indicated by the ALUDEC 107, thereby moving the execution result value α-1 to the TA register 114. Then, the value Va stored in the TB register 113 returns to the register of the RAM 110. In this way, the inspection of the LW 110 is completed.

Next, check the SP (stack pointer lower 16 bits: 109), which is the stack pointer with the lower 16 bits of the register storing the data in interrupt processing. The value Vb of the SP 109 is stored in the TB register 1113. In addition, the execution result value α-1 of the TA register 114 is transferred to the SP 109 and is transferred to the ALU 1111 therefrom. At the same time, the CPU monitor macro service code 110 specifies the operation of the ALU 11l via the ALUDEC 107. In this way, the ALU 111 performs the decrement operation specified by the ALUDEC 107 and thereby transfers the execution result value α-2 to the TA register 11l4. The value Vb stored in the TB register 113. Returns to the SP 109. In this way, the inspection of the SP l09 is completed.

It also examines the increment and decrement operations at SPH (stack pointer upper 8 bits: 108), which include the upper 4 bits of the register for storage. First, the value Vc of the SPH 108 is stored in the TB register 113, and the value α-2 of the TA register 114 is transferred to the SPH 108. Then, the CPU monitor macro service code 102 transmits the data FFFF (H) to the ALU 111 via the TA register 1114, and specifies the operation of the ALU 111 via the ALUDEC 1107. Thus, the ALU 111 implements the increment operation specified by the ALUDEC 107. By the increment operation, the carry flag of the ALU register 126 becomes 1, thereby reducing the value α-2 of the SPH 108 to the value α-3. The value α-3 of the SPH 108 is transferred to the TA register 114. The value Vc stored in the TB register 113 returns to the SPH 108. In this way, the inspection of the SPH 108 is completed.

It also checks the path from TQ (Instruction Code Latch 104) to the RAM 110 address indicated by RAMAD 105, which is an instruction code latch that fetches instruction code. By accessing the TQ 104, the CPU monitor macro service code 102 writes the data Vd present in the RAM 110 address 0080 (H) indicated by the TRA (LW Address Temporary Register: 106) to the TB register l13. TRA 106 is a register that stores an address associated with RAM 110. The value α-3 of the TA register 114 is transferred to the LW 110 address AA indicated by the TRA 106, and from this to the ALU 111. In addition, the CPU monitor macro service code 102 specifies the operation of the ALU 111 via the ALUDEC 107, whereby the ALU 111 executes a reduction operation specified by the ALUDEC 107 to execute the execution result value α. -4) to the TA register 114. The value Vd stored in the TB register 113 then returns to the Lm 110 address 0080 (H) designated by the TRA 106. In this way, the path check associated with the RAM 110 is completed.

CPU monitor macro service code 102 also sends address 000 (H) to TQ 104 to check TQLL 121, which is comprised of the least significant four bits of TQ 104. The data Ve of the RAM 110 address AB indicated by the TQLL 121 is stored in the TB register 113 through the ALU 111. The value α-4 of the TA register 114 is transferred to the RAM 110 address AB indicated by the RAMAD 105, and is transferred to the ALU 111 therefrom. The CPU monitor macro service code 102 then specifies the operation of the ALU 111 via the ALUDEC 107, whereby the ALU 111 executes the decrement operation specified by the ALUDEC 107 to execute the execution result value ( α-5) is moved to the TA register 114. The value Ve stored in the TB register 113 then returns to the RAM 1110 address AB designated by the TQLL 121. In this way, the inspection of the TQLL 121 is completed.

The TQHH 124 then checks the path to the RAM 110 address indicated by the TQHH 124, which is composed of the most significant four bits of the TQ 104. The data Vf of the RAM 110 address AC indicated by the TQHH l24 is stored in the TB register 113. The value α-5 of the TA register 114 is transferred to the RAM 11 address AC indicated by the TQHH l24, and is transferred to the ALU 111 therefrom. The CPU monitor macro service code 102 specifies the operation of the ALU 111 via the ALUDEC 107, whereby the ALU 111 implements the reduction operation specified by the ALUDEC 107 to execute the execution result (α-6). ) Is moved to the TA register 114. The value Vf stored in the TB register 113 returns to the RAM 110 address AB designated by the TQHH 124.

After checking the peripheral function, the SFR output destination address β of the TC register 112 is moved to the TB register 113, and the value α-6 of the TA register 114 is transferred to the TC register 112. Transferred. The CPU monitor macro service code 102 specifies the operation of the ALU 111 via the ALUDEC 107, whereby the ALU 111 determines the value α-6 of the TA register 114 and the TC register 112. Compare the value α-6. If there is a match, the value α-6 of the TA register 114 is transferred to the ALU 111, where the ALU 111 is a decrement operation specified by the CPU monitor macro service code 102 via the ALUDEC 107. Is executed to transmit the resultant result α-7 to the TA register 114.

According to the designation of the CPU monitor macro service code 102 via the ALUDEC 107, the ALU 111 generates a value? -7 stored in the TA register 114 and a value? Of the TC register 112, i.e. Compare the SFR output destination address (β). In a different case, the value α-7 of the TA register 114 is output to the ALU 111, whereby the ALU 111 performs the reduction operation specified by the ALUDEC 107 on the value α-7. The execution result α-8 is transferred to the TA register 114, where the value α-8 represents the CPU diagnostic result.

Finally, the value α-8 of the TA register l14 that stores the execution result data of the CPU diagnostics is output to the outside 120 of the microcomputer 125 in accordance with the SFR output address stored in the TB register 113. . Thus, the user can externally check the state of the CPU with reference to the value α-8.

As described above, the CPU can be diagnosed by a CPU monitor macro service that executes a series of instructions using an internal interrupt. In this method, the time required for reading an instruction can be reduced as compared with the conventional method of reading externally using a CPU self-diagnosis program. Thereby, even when installed on the user board, the CPU of the microcomputer can be diagnosed quickly.

According to the present invention, it is possible to quickly diagnose the CPU of the microcomputer.

Claims (2)

A microcomputer having a self-diagnosis unit for diagnosing the CPU of the microcomputer by executing a series of instructions by a CPU, a randomly readable RAM, an interrupt processing unit, a data bus, an input / output port, and an external interrupt signal. A CPU monitor macro service which is a program, a CPU diagnostic unit for diagnosing a CPU of the microcomputer according to the CPU monitor macro service with reference to data supplied from the outside in advance, and the CPU diagnostic unit using the data supplied from the outside And an output unit for outputting a diagnosis result to the outside of the microcomputer. A microcomputer comprising a self-diagnosis unit, which executes a series of instructions by a CPU, a randomly readable and writeable RAM, an interrupt processing unit, a data bus, an input / output port, and an external interrupt signal to diagnose the CPU of the microcomputer. A CPU monitor macro service which is a program, a start unit for starting the CPU monitor macro service, a micro ROM which is an instruction code storage space for storing command codes of the CPU monitor macro service, and an instruction code of a CPU monitor macro service of the micro ROM. And a first register for recording and storing an initial value for performing the CPU diagnosis in a RAM using a user program of an external memory prior to initiating the CPU monitor macro service, and a user program of the external memory. Initial value written to the RAM using A second register for storing an address indicating an output destination for the result value of the execution after executing the CPU diagnostics, and using the initial value to check the address of RAM and the path thereof to store the data in interrupt processing ( a third register to save, a destination unit indicating the third register, a fourth register to store the result of the arithmetic operation by the arithmetic unit implementing the arithmetic operation on the execution result value of the check, and after the check An output unit for storing the result from the fourth register to the first register and outputting an execution result value stored in the first register to the outside of the microcomputer through a port indicated by the second register, C of the microcomputer with reference to the execution result value outside of the microcomputer Microcomputer characterized in that the state of the PU is diagnosed.